Various types of slide lock device for a press machine have been implemented in practice that can lock a slide of the machine so that, during repairs to the press machine, repairs to a die, exchange of a die, and so on, the slide does not shift downward with respect to the main body of the machine.
The slide lock device described in Patent Document #1 is a slide lock device that, by engaging a plurality of engagement claws with gear teeth of a large sized helical gear that raises and lowers the slide via an eccentric mechanism, locks the helical gear in any desired position.
And the slide lock devices for press machines described in Patent Document #2 and #3 are slide lock devices that are capable of locking a slide of a press machine by locking a crank shaft that rotates together with the raising and lowering operation of the slide, so that the crank shaft cannot rotate.
Each of these slide lock devices comprises: a flange member having a barrel portion that is fitted over the crank shaft and is fixed thereto and a flange portion that extends peripherally outward from the end portion of the barrel portion along a plane that is orthogonal to the axis of the crank shaft, a main body member that is fixed to a main body frame of the press machine and that is fitted over the barrel portion so that it is rotatable relatively thereto, an auxiliary body member that is disposed to oppose the flange portion from the side opposite to the main body member, four reception holes formed in the main body member, four pin members that are installed in the four reception holes so as to be shiftable therein, a plurality of arcuate entry holes formed in the flange portion, four support holes formed in the auxiliary body member, and four air cylinders that are capable of driving the four pin members forward and backward in the axial direction of the crank shaft.
When the slide is to be locked, the pin members are driven forward so as to pass through the entry holes and to pass into the support holes; and, when the slide is to be unlocked, the pin members are driven to retract, so that they are removed from the support holes and the entry holes.
In the case of the slide lock device described in Patent Document #3, an annular first locking member is provided between the main body member and the flange portion, a first locking mechanism is provided that is capable of locking the four pin members in their retracted positions with the first locking member, an annular second locking member is provided on the outer surface side of the auxiliary body member, and a second locking mechanism is provided that is capable of locking the four pin members in their advanced positions with the second locking member.